OBJECTIVES: To compare the effect of glycated hemoglobin (HbA1c%) control on cognition in outpatients with type 2 diabetes in the endocrinology clinics at Hospital Pulau Pinang, Malaysia, between February and September 2017.

METHODS: The study is a prospective cohort study, where 179 patients with uncontrolled glycemia (UCG) and 101 patients with controlled glycemia (CG) were assessed to identify demographics data, laboratory and cognitive tests. The target of glycemic control was defined as (HbA1c ≤7% (53 mmol/mol) for patient <65 years, and <8% (64 mmol/mol) for patient ≥65 years). Pre-designed and validated Mini-Addenbrooke’s cognitive examination (M-ACE) (Malay version) was used to assess cognitive dysfunction. The cut-off score ≤21 of M-ACE was considered as a cognitive deficiency. IPM SPSS V23 was used for data analysis.

RESULTS: The age of uncontrolled and controlled glycemia groups were (57.5 ± 10.6) and (63.3 ± 10.8) years respectively. About 78 (43.6%) cases of UCG cohort shown to have cognition deficit, while 29 (28.7%) cases with CG have cognitive decline (P-value <0.001). Spearman correlation indicated a statistically significant association between uncontrolled glycemia and cognitive damage (r: 0.147, P-value: 0.014). The relative risk (RR) of cognitive deficiency in persons with uncontrolled glycemia is statistically significant (RR: 1.52, 95% CI: 1.1 – 2.2) and the excess relative risk (ERR) is 52%. The absolute risk (AR) is 14.9%, and the number needed to harm (NNH) is 7.

CONCLUSIONS: The study has demonstrated that patients with uncontrolled glycemia are at a higher risk of cognitive impairment than patients with controlled glycemia.